Abstract:

The mechanical properties of unsaturated soils in superficial layer is closely related with soilwater characteristics. Researching on the soilwater characteristics under geostatic stress and the deformation under 1-D stress state is important for stability analysis in slope and foundation pit excavation. To investigate the effect of 1-D stress and suction on the deformation of silty sand in southwest China, we carried out drying tests and consolidation tests by using a k 0 stress controllable pressure plate apparatus. Test results show that given low vertical stress state, the stress variation in a small range has little influence on soil-water characteristic curve. Under certain net vertical stress, the volumetric strain of silty sand increases linearly with the increase of suction. Under certain suction, the consolidation deformation under k0 stress is non-linearly elastic. As net vertical stress increases，the volumetric strain increases and the void ratio reduces.

Key words: one-dimensional stress(1-D), silty sand, soil-water characteristic curve(SWCC), deformation